[Giant cell tumor of the tendon sheath: characteristic findings of the bone scintigraphy and correlation with MRI]

We report 3 cases of an unusual tumor, that is, the giant cell tumor of the tendon sheath. The patients consulted due to the appearance of a well-defined, painless, soft tissue mass with mild-to-moderate inflammation located in the thumbs or toes. These clinical data, together with the bone scan findings, oriented the diagnostic suspicion that was confirmed by a pathology study of the tumor after resection. This work has aimed to review the characteristics of the bone scan (BS) image of this tumor and its correlation with the conventional X-ray imaging and magnetic resonance imaging (MRI).

[67 Ga-citrate scintigraphy as a determiner in the diagnosis of a subacute thyroiditis]

We present the case of a 41-year-old man admitted to the hospital with fever and toxic syndrome possibly having an oncological or infectious origin. A whole body scan with 67Ga-citrate showed an intense and diffuse radiotracer accumulation in the thyroid gland. The patient was re-evaluated and studied with other diagnostic tests including a thyroid 99mTc-pertechnetate scintigraphy and a thyroidal radioiodine uptake. A correct final diagnosis of painless subacute thyroiditis was made.

Somatostatin receptor scintigraphy predicts impending cardiac allograft rejection before endomyocardial biopsy

The invasive nature of endomyocardial biopsy has led to a search for alternative diagnostic modalities for the detection of cardiac allograft rejection. To date, no non-invasive test meets all the requirements for the detection of acute and chronic rejection. The rejection process usually presents with lymphocyte infiltration with or without myocyte necrosis, which indicates the severity of cardiac allograft rejection and the necessity of treatment. Activated lymphocytes express somatostatin receptors; thus somatostatin receptor imaging could be used to target them. The aim of this study was to assess the feasibility of using somatostatin receptor imaging to target activated lymphocytes in the process of cardiac allograft rejection. Thirteen somatostatin receptor imaging studies were performed on ten cardiac allograft recipients 12-4,745 days after transplantation, simultaneously with endomyocardial biopsy, to assess the imaging of activated lymphocytes in comparison with histological findings. Somatostatin receptor imaging was performed 4 h after the injection of 110 MBq of the somatostatin analogue indium-111 pentetreotide. 111In-pentetreotide uptake was visually scored and semi-quantitatively estimated by the calculation of a heart-to-lung ratio (HLR). The visual score correlated with the HLR. Intense/moderate uptake on visual assessment and an HLR >1.6 was observed in eight studies. In three of these studies there was significant rejection in the simultaneous endomyocardial biopsy [International Society of Heart and Lung Transplantation (ISHLT) rejection grade 3A/4]. Intense/moderate uptake was associated with mild or no rejection in the remaining five patients, and in four of them the next endomyocardial biopsy performed 1 week later demonstrated significant rejection requiring treatment. Two patients with low uptake and an HLR <1.6 had no evidence of rejection either in the simultaneous endomyocardial biopsy or in the endomyocardial biopsy performed the following week. These preliminary results indicate the feasibility of targeting activated lymphocytes with somatostatin receptor imaging in the detection of cardiac allograft rejection. Somatostatin receptor imaging may predict impending rejection at least 1 week before the endomyocardial biopsy becomes positive. The late appearance of diagnostic endomyocardial biopsy probably reflects a lag-time between lymphocytic activation and induction of myocyte damage. Furthermore, somatostatin receptor imaging at 4 h may in any case allow earlier intervention in the event of rejection, given the time required for histological processing of endomyocardial biopsy.

Marked ventricular repolarization abnormalities in highly trained athletes' electrocardiograms: clinical and prognostic implications

OBJECTIVE

We sought to study the functional, clinical and prognostic implications of marked repolarization abnormalities (MRA) sometimes seen in athletes' electrocardiograms (ECGs).

BACKGROUND

The clinical meaning of ECG MRA in athletes is unknown. No relationship has been drawn between either training intensity or any particular type of sport and MRA. Athletes are usually symptom free and do not show any decrease in their physical performance. It is as yet unclear whether MRA may have a negative effect on the performance of such athletes in competitive sports.

METHODS

We studied 26 athletes with MRA (negative T waves > or =2 mm in three or more ECG leads at rest). No athletes presented clinical symptoms of cardiac disease or decrease in their physical performance. Clinical and physical examinations, ECG at rest, exercise test and echocardiographic and antimyosin studies were performed in all athletes. Rest/exercise myocardial perfusion single-photon emission computed tomography studies were performed in 17 athletes. The follow-up ranged from 4 to 20 years (mean 6.7 years).

RESULTS

Four athletes were excluded due to hypertrophic cardiomyopathy. Echocardiographic studies showed right and left normal ventricular dimensions for highly conditioned athletes. In the exercise test, heart rate was 166 +/- 12.4 beats/min, and exercise tolerance was 15.2 +/- 2.7 metabolic equivalents of the task. All athletes had ECG at rest simulating myocardial ischemia or "pseudoischemia" with a tendency to normalize during exercise. Myocardial perfusion studies were normal in the studied athletes. Antimyosin studies showed mild and diffuse myocardial radiotracer uptake in 15 athletes (68%). No adverse clinical events were observed in the follow-up.

CONCLUSIONS

These results suggest that MRA have no clinical or pathological implications in athletes and should, therefore, not preclude physical training or participation in sporting events.

Myocardial sympathetic innervation in the athlete's sinus bradycardia: is there selective inferior myocardial wall denervation?

BACKGROUND

Sinus bradycardia in trained athletes is predominantly a manifestation of increased vagal tone, but it is not known whether an alteration in the cardiac sympathetic system can contribute to blunted chronotropic response. This study assessed the integrity of the sympathetic system in trained athletes with sinus bradycardia by means of the iodine-123-metaiodobenzylguanidine (123I-MIBG) procedure.

METHODS AND RESULTS

Fourteen athletes with sinus bradycardia and 8 athletes with a normal heart rate were explored by means of planar and single photon emission computed tomography MIBG studies. The heart/mediastinum ratio, regional myocardial distribution, and percent of regional myocardial MIBG uptake were evaluated. The heart/mediastinum ratio in athletes with sinus bradycardia was 1.87+/-0.10, and in athletes with a normal heart rate, the heart/mediastinum ratio was 1.86+/-0.16 (P = not significant). In athletes with sinus bradycardia, the regional distribution of MIBG showed an inferior and apical uptake defect in 8 athletes, an inferior, apical, and septal defect in 3 athletes, an inferior defect in 1 athlete, and normal distribution in 2 athletes (14%). In athletes with a normal heart rate, the regional distribution of MIBG showed an apical uptake defect in 3 athletes and normal distribution in 5 athletes (63%). The percent of regional MIBG uptake in the inferior region was significantly reduced in athletes with sinus bradycardia (44%+/-13% vs. 72%+/-11%, P<.01).

CONCLUSION

These results show severely reduced myocardial MIBG distribution in the inferior region in athletes with sinus bradycardia, suggesting selective inferior myocardial wall sympathetic denervation, which may be related to increased vagal tone.

Relationship between cerebral perfusion in frontal-limbic-basal ganglia circuits and neuropsychologic impairment in patients with subclinical hepatic encephalopathy

Early detection of neuropsychologic impairment in cirrhotic patients with subclinical hepatic encephalopathy (SHE) is important for their prognosis and quality of life. Abnormal MRI and MR spectroscopy (MRS) findings have been proposed as early markers of brain damage in these patients, but the role of functional neuroimaging in this field still has to be defined. In this study, the SPECT perfusion pattern in patients with SHE was investigated, and the relationship between regional cerebral blood flow (rCBF) and the MRI, MRS, neuropsychologic evaluation and biochemical data of these patients was assessed.

METHODS

Data were obtained from 13 cirrhotic patients with SHE and 13 age-matched healthy volunteers. Fasting venous blood ammonia and manganese sampling and a battery of standardized neuropsychologic tests related to basal ganglia function and sensitive to the effects of liver disease were all performed on the same day. MRI and 99mTc-hexamethyl propyleneamine oxime SPECT were performed within 2 wk.

RESULTS

A pattern of decreased prefrontal rCBF was found in patients with SHE compared with healthy volunteers. Basal ganglia and mesial temporal rCBF correlated inversely with performance on motor tasks involving speed (Purdue pegboard test) and frontal premotor function (Luria graphic alternances and Stroop tests). Thalamic rCBF correlated positively with T1-weighted MRI signal hyperintensity in the globus pallidus and with abnormal MRS findings. Neither the MRI signal intensity of the globus pallidus nor MRS correlated with neuropsychologic test results.

CONCLUSION

Cirrhotic patients with SHE show a SPECT pattern of impaired prefrontal perfusion that does not seem to account for their neuropsychologic deficits. On the other hand, perfusion in some parts of the limbic system and limbic-connected brain regions, such as the striatum and the mesial temporal regions, increased with neuropsychologic impairment. These findings suggest that brain SPECT may be more sensitive than MRI in delineating cirrhotic patients requiring in-depth clinical testing to reveal basal ganglia-related neuropsychologic alterations.

Influence of exercise rehabilitation on myocardial perfusion and sympathetic heart innervation in ischaemic heart disease

Exercise rehabilitation improves the clinical status in ischaemic heart disease. The purpose of this study was to assess the influence of exercise rehabilitation on myocardial perfusion and sympathetic heart innervation. Sixteen patients with ischaemic heart disease and previous myocardial infarction were investigated by means of exercise/rest tetrofosmin and metaiodobenzylguanidine (MIBG) exercise/rest single-photon emission tomography (SPET) studies, before and 6 months after starting an exercise rehabilitation programme. Tomograms were divided into 15 segments, and these were grouped into five myocardial anatomical regions. Regional uptake of both tracers was quantified and expressed as a percentage of maximum peak activity. The percentage < or =55% was chosen to evaluate defect size, and the results were expressed as a percentage of left ventricular mass. Areas with perfused and denervated myocardium and areas with ischaemic myocardium were calculated. In addition, regions with <75% of peak activity in the exercise perfusion study at baseline were divided into two groups according to whether there was an increase in peak activity of >10% (representing reversible regional defects) or an increase of <10% (representing fixed regional defects) in the rest study. These percentages were compared with the percentages obtained in the innervation study, and with the percentages obtained in exercise/rest perfusion and innervation studies performed 6 months after starting rehabilitation. Myocardial perfusion defects were significantly smaller than myocardial innervation defects before and 6 months after starting exercise rehabilitation. The area of ischaemia 6 months after starting exercise rehabilitation was significantly smaller than that before rehabilitation (0.31%+/-1.4% vs 1.4%+/-1.6%, P<0.01). The size of innervation defects and the area of perfused and denervated myocardium did not show significant differences between the two studies performed before and 6 months after starting exercise rehabilitation. In reversible regional defects the percentage of peak activity was significantly increased 6 months after starting exercise rehabilitation in exercise and rest studies (P<0.001), while in fixed regional defects it was significantly increased only in exercise studies (P<0.001). There was no significant change in the regional MIBG percentages. We conclude that in ischaemic heart disease, exercise rehabilitation over a period of 6 months improves myocardial perfusion, but does not cause changes in sympathetic myocardial innervation.

Genetic, clinical, and biochemical analysis of unrelated Spanish families with multiple endocrine neoplasia type I

OBJECTIVE

(1) To study seven unrelated Spanish families with multiple endocrine neoplasia type I (MEN I), describing clinical features and investigating the presence of germline mutations in the MEN1 gene, and (2) to establish reference values for pancreatic polypeptide and gastrin after a standardized test meal in a healthy control group, analyzing the usefulness of this test for detecting neuroendocrine gastroenteropancreatic tumors in subjects with MEN I.

METHODS

Two or three generations of 7 kindreds with MEN I, consisting of a total of 39 individual family members, were investigated. Three of the families were subjected only to genetic analysis, and the other four families were also assessed clinically. A group of 23 healthy control subjects were also studied.

RESULTS

Mutations in the MEN1 gene were found in six of the seven families studied. Of the 4 families studied clinically, 12 family members were genetically affected. In these study subjects, hyperparathyroidism, adrenal adenomas, neuroendocrine gastroenteropancreatic tumors, and pituitary adenomas developed in 100%, 50%, 16%, and 12%, respectively. All demonstrated pancreatic tumors were associated with abnormal results after a test meal, but 75% of them also showed high basal hormonal measurements.

CONCLUSION

Analysis of the MEN1 gene decreases the total number of subjects who need to undergo repeated clinical and biochemical studies, but genetic mutations are not detected in all families with MEN I. Hyperparathyroidism is the most common manifestation of the syndrome, but the presence of adrenal adenomas has probably been underestimated. Ingestion of a standardized test meal for stimulation of gastrin and pancreatic polypeptide could be a complementary procedure for diagnosing gastroenteropancreatic tumors in selected patients with MEN I in whom basal gastrin and pancreatic polypeptide levels are normal.

Sympathetic reinnervation of cardiac allografts evaluated by 123I-MIBG imaging

Some heart-transplant patients present with improved heart rate response to exercise and anginal pain suggesting reinnervation of allografts. Studies performed up to 5 y post-transplantation have suggested that reinnervation is a slow process that occurs only after 1 y post-transplantation. The purpose of this study was to evaluate the extent of sympathetic reinnervation in heart-transplant patients and its relation to cardiac function.

METHODS

We performed 123I-metaiodobenzylguanidine (MIBG) studies and rest/exercise radionuclide ventriculography in 31 heart-transplant patients 6 mo to 12 y post-transplantation. Intensity of myocardial MIBG uptake was quantified by a heart-to-mediastinum ratio (HMR), and the regional distribution of MIBG was determined by tomographic studies.

RESULTS

HMR correlated positively with time after transplantation (r = 0.607, P < 0.001). Patients studied from 2 to 12 y post-transplantation had an HMR significantly higher than patients studied before 2 y post-transplantation (1.62 +/- 0.2 versus 1.34 +/- 0.2, P < 0.05). Myocardial MIBG uptake was anterolateral in 16 patients, anterior in 3 and anterolateral and septal in 3. Myocardial MIBG uptake was absent in 9 patients. Vasculopathy developed in 8 patients, and 5 of them (63%) had decreased myocardial MIBG uptake. Peak filling rate was higher in patients studied from 2 to 12 y post-transplantation (2.7 +/- 0.8 end-diastolic volume (EDV)/s versus 2.16 +/- 0.5 EDV/s, P = 0.02).

CONCLUSION

Sympathetic reinnervation increases with time after heart transplantation and is seen more frequently after 2 y post-transplantation. Complete reinnervation of the transplanted heart does not occur even up to 12 y post-transplantation. Early vasculopathy may delay the process of sympathetic reinnervation.

[Isotopic study with double phase 99mTc-sestamibi in the localization of parathyroid gland lesions]

BACKGROUND

The use of preoperative imaging in patients with hyperparathyroidism remains controversial. The aim of this study is to assess the usefulness of the double-phase 99mTc-sestamibi scintigraphy in the diagnosis of abnormal parathyroid glands in patients with primary hyperparathyroidism.

PATIENTS AND METHODS

We studied 60 patients presenting with primary hyperparathyroidism who were referred to surgery; four of them had been unsuccessfully operated. 99mTc-sestamibi scintigraphy were performed in all patients previously to surgery. Scintigraphic technique: planar imaging of the neck and thorax was done in the anterior view at 15 and 150 min postinjection of 740 MBq (20 mCi) of 99mTc-sestamibi.

RESULTS

Surgery found 57 adenomas (2.59 [SD, 5.84] g; range 0.160-40), 6 hyperplastic glands (0.34 [SD, 0.26] g) and one carcinoma 8.2 g. The 99mTc-sestamibi was able to localize correctly 60 out of 64 lesions (55/57 adenomas, 4/6 hyperplastic glands and 1/1 carcinoma) (global sensitivity of 94%, adenomas sensitivity of 96%, positive predictive value of 97% and specificity of 98%). Isotopic imaging detected the abnormal tissue in all patients who had undergone unsuccessful previous surgery. PTH (4 [SD, 1.51] pmol/l) and calcium postoperative serum levels (2.13 [SD, 0.22] mmol/l) showed curation of all patients.

CONCLUSION

Double phase parathyroid scintigraphy with 99mTc-sestamibi is the method of choice to localize abnormal parathyroid glands.

Regional cerebral blood flow changes in chronic alcoholic patients induced by naltrexone challenge during detoxification

The recent introduction of the opioid antagonist naltrexone for alcohol-dependence therapy has been mainly based on behavioral animal models that provide evidence of the involvement of the endogenous opioid system in alcohol drinking and dependence. However, the neurophysiological mechanisms of the effect of naltrexone in alcoholic patients remain unknown. This study investigates the effects of a naltrexone challenge on regional cerebral blood flow (rCBF) in chronic alcoholic patients during detoxification.

METHODS

Sixteen alcoholic inpatients underwent two 99mTc-hexamethyl propyleneamine oxime (HMPAO) brain SPECTs: a basal SPECT on day 10 of abstinence and a second SPECT on day 12 of abstinence after oral administration of 150 mg naltrexone. Region-to-cerebellar ratios were obtained for the orbitary frontal, prefrontal, lateral temporal and mesial temporal regions, basal ganglia and thalamus in each hemisphere. A percentage of rCBF change between both SPECTs was calculated for each region as 100 x (naltrexone - baseline)/ baseline. Values from 13 brain SPECTs of age-matched normal volunteers including test-retest measurements were used for statistical comparison.

RESULTS

In baseline conditions, alcoholics showed lower rCBF than controls in left orbitofrontal cortex (84.0+/-5.1 versus 89.8+/-5.0, P < 0.01) and prefrontal cortex (left hemisphere: 87.4+/-5.2 versus 96.2+/-3.6, P < 0.001; right hemisphere: 87.0+/-4.9 versus 95.8+/-4.2, P< 0.001). After naltrexone, a significant rCBF decrease was found versus test-retest values in left basal ganglia (-3.3%+/-4.0% versus 1.5%+/-4.1%, P< 0.05), right basal ganglia (-4.2%+/-4.9% versus 0.6%+/-2.7%, P < 0.01) and left mesial temporal region (-4.5%+/-6.8% versus 2.2%+/-2.9%, P < 0.01).

CONCLUSION

The rCBF decrease detected by SPECT after naltrexone challenge in structures rich in opioid receptors, such as the basal ganglia and the left mesial temporal region, may reflect a naltrexone-induced decreased metabolic activity in these areas. These results support the involvement of the opioid system in alcohol dependence. Furthermore, the localization of naltrexone-induced rCBF changes in mesial temporal structures and in basal ganglia supports the implication of emotional memory and obsessive-compulsive phenomena in craving.

[The effect of a race 4 hours in duration on the production of beta-endorphin and adrenocorticotropic hormone]

BACKGROUND

Physiological hormone adaptation to a prolonged and submaximum exercise is not well known. The present study was designed to evaluate changes in plasma levels of beta-endorphin and ACTH before and after a 4 hour pedestrian race.

SUBJECTS AND METHOD

Fourteen amateur athletes enrolled in a 4-hour race were studied. Beta-endorphin and ACTH determinations were performed (double antibody IRMA) 10 minutes before and after the race. Simultaneously, heart rate and blood pressure were registered.

RESULTS

After the race beta-endorphin level increased 2.8 times with respect to basal values (X [DE]) (42.2 [20,5] VS 14.9 [5.1] pM/I; p < 0.0001), and ACTH level increased 3.5 times (110.8 [72.9] vs 31.4 [14.2] pg/ml; p < 0.0001). There was a positive correlation between the increase of beta-endorphin and ACTH and the distance covered by each athlete (r = 0.617, p < 0.001 and r = 0.533, p < 0.05, respectively), and between the increase of basal and post-race values of both hormones (r = 0.935; p < 0.001).

CONCLUSION

Prolonged and submaximum exercise provokes beta-endorphin and ACTH increase, and is related to the amount of performed exercise. There is a positive correlation between the increase of plasma levels of both hormones. Therefore, exercise amount could be one of the main modulator mechanism of beta-endorphin and ACTH release.

Use of somatostatin analogue scintigraphy in the localization of recurrent medullary thyroid carcinoma

Detection of recurrence of medullary thyroid carcinoma (MTC) remains a diagnostic problem. Increased serum tumour marker levels frequently indicate recurrence while conventional imaging techniques (CIT) are non-diagnostic. In this study, we performed indium-111 octreotide scintigraphy and CIT in a series of 20 patients with MTC presenting with elevated serum tumour markers after surgery. 111In-octreotide whole-body studies detected 15 pathological uptake foci in 11 of the 20 patients studied and CIT detected 17 lesions in 11 of the 20 patients. Ten patients underwent reoperation, five of them with positive 111In-octreotide scintigraphy and CIT and two with positive isotopic exploration and negative CIT. Surgical findings demonstrated that the results of isotopic study and CIT had been false-positive for MTC in one case (sarcoidosis). The six patients with true-positive 111In-octreotide studies had significantly higher basal calcitonin (CT) and carcinoembryonic antigen (CEA) levels than the patients with negative isotopic studies. The expression of somatostatin receptor (SSTR) subtypes by PC-PCR could be investigated in four cases with a positive isotopic study. Among the three cases with a true-positive study, SSTR2, the SSTR subtype that preferentially binds to the somatostatin analogue octreotide, was detected in two, SSTR5 was demonstrated in the three, and SSTR3 was detected in one. No subtype of SSTR was detected in the case with a final diagnosis of sarcoidosis. We conclude that 111In-octreotide has limited sensitivity in detecting recurrence in patients with MTC, although its sensitivity may improve with high serum CT levels. This radionuclide imaging technique should be employed when conventional imaging techniques are negative or inconclusive or when the presence of somatostatin receptors may provide the basis for treatment with somatostatin analogues.

Efficacy of augmented immunosuppressive therapy for early vasculopathy in heart transplantation

OBJECTIVES

The present study was undertaken to prospectively and comparatively evaluate the role of serial myocardial perfusion imaging and coronary angiography for the detection of early vasculopathy in a large patient population and also to determine the short- and long-term efficacy of augmented immunosuppressive therapy in the potential reversal of the early vasculopathy.

BACKGROUND

Allograft vasculopathy is the commonest cause of death after the first year of heart transplantation. Anecdotal studies have reported the efficacy of augmented immunosuppressive therapy after early detection of vascular involvement. However, no prospective study has evaluated the feasibility of early detection and treatment of allograft vasculopathy.

METHODS

In 76 cardiac allograft recipients, 230 coronary angiographic and 376 scintigraphic studies were performed in a follow-up period of 8 years. Angiography was performed at 1 month and every year after transplantation, and thallium-201 scintigraphy at 1, 3, 6 and 12 months after transplantation and twice a year thereafter. Prospective follow-up of 76 patients showed that 18 developed either angiographic or scintigraphic evidence of coronary vasculopathy. All episodes were treated with 3-day methylprednisolone pulse and antithymocyte globulin.

RESULTS

Twenty-two episodes of vasculopathy were diagnosed and treated in these 18 patients. Of these 22 episodes, two were detected only by angiography, seven by both angiography and scintigraphy, four by scintigraphy and histologic evidence of vasculitis and nine episodes only by thallium-201 scintigraphy studies. Angiographic and/or scintigraphic resolution was observed in 15 of the 22 episodes (68%) with augmented immunosuppression. The likelihood of regression was higher when treatment was instituted within the first year of transplantation (92%) than after the first year (40%) (p = 0.033). Eighty percent of patients who responded to follow-up.

CONCLUSIONS

The present study suggests that early detection of allograft coronary vasculopathy is feasible with surveillance myocardial perfusion or coronary angiographic studies. When identified early after transplantation, immunosuppressive treatment may result in regression of coronary disease.

Myocardial damage does not occur in untreated hyperthyroidism unless associated with congestive heart failure

Even in the absence of underlying cardiac disease, hyperthyroidism has seldom been reported to be associated with left ventricular dysfunction and congestive heart failure. The left ventricular function invariably improves with achievement of euthyroid status. Anecdotal autopsy reports have suggested that myocardial necrosis associated with hyperthyroidism may be responsible for congestive heart failure. This study prospectively evaluates the role of myocardial necrosis in untreated hyperthyroidism by imaging with Indium-111 antimyosin antibody. Thirteen consecutive patients (7 men and 6 women, mean age 36 +/- 11 years) with hyperthyroidism and Graves' disease (10 patients), subacute thyroiditis (2 patients), or multinodular goiter (1 patient) formed the basis of the study. The T4 levels ranged from 33 to 183 pmol/L (mean 103 +/- 47 pmol/L) and cardiac output from 5.47 to 11.0 L/min (mean 7.17 +/- 1.75 L/min). Two patients had clinical congestive heart failure and mildly depressed left ventricular ejection fraction. Both patients had scintigraphic evidence of myocardial damage with abnormal antimyosin scans. In the remaining 11 patients with normal left ventricular ejection fraction, no antimyosin uptake was observed. The reevaluation of two patients with abnormal initial scans 6 to 8 months after treatment revealed euthyroid status, resolution of antimyosin uptake, and normalization of left ventricular function. This study indicates that myocardial necrosis may be detected in a small proportion of patients with hyperthyroidism, which could contribute to left ventricular systolic dysfunction.

Nitrate administration to enhance the detection of myocardial viability by technetium-99m tetrofosmin single-photon emission tomography

A comparison was performed between technetium-99m tetrofosmin myocardial perfusion tomography at baseline and after nitrate administration, using a 2-day protocol, and rest-reinjection thallium-201 single-photon emission tomography (SPET) studies in order to assess whether nitrates enhance the detection of viable myocardium with 99mTc-tetrofosmin. Fifteen patients with coronary artery disease, previous myocardial infarction and a left ventricular ejection fraction <40% underwent 201Tl rest-injection and 99mTc-tetrofosmin baseline-postnitroglycerin (0.4 mg sublingually) SPET studies, within 48 h. Tomograms based on the three spatial planes were divided into 15 segments and regional tracer uptake was quantitatively analysed. Viability was defined as presence of tracer uptake >/=50% of peak activity on baseline studies or after reversibility. The percentage of peak activity of 99mTc-tetrofosmin at baseline correlated with that of 201Tl (r=0.82, P <0.001). On baseline 99mTc-tetrofosmin studies, 73 of the 225 segments that were analysed had <50% of peak activity. Fifteen percent of these segments showed reversibility after nitrate administration, with an increase in 99mTc-tetrofosmin uptake from 40%+/-9% to 57%+/-9% of peak activity (P=0.003). All reversible segments after nitrate administration had viability criteria on 201Tl studies, but 20 segments that were non-viable on 99mTc-tetrofosmin studies were viable on 201Tl studies. Using a threshold value of >/=40% of peak activity, only seven segments remained non-viable on 99mTc-tetrofosmin studies. Overall agreement between 99mTc-tetrofosmin with nitrates and 201Tl-reinjection regarding the presence of myocardial viability was 90%. Detection of myocardial viability with 99mTc-tetrofosmin was enhanced after nitrate administration, correlating with viability criteria observed on thallium studies.

Efficacy of preoperative diagnostic imaging localization of technetium 99m-sestamibi scintigraphy in hyperparathyroidism

BACKGROUND

Until now, preoperative parathyroid imaging has been considered unnecessary because currently available techniques do not provide any better results than an expert surgeon. We conducted a multicenter prospective study evaluating the capability of technetium 99m sestamibi scintigraphy in the preoperative identification of pathologic glands.

METHODS

Ninety-three patients with hyperparathyroidism, seven of them reoperative cases, were studied. In addition, 20 age-matched normocalcemic control subjects were also studied.

RESULTS

Surgical confirmation of scintigraphic images was obtained in 91 of 93 cases (sensitivity, 97.8%). In all reoperative cases (n = 7), in all cases of ectopic glands (whether operated or not; n = 6), and in all patients with a single-gland disease (n = 70), topographic identification of the pathologic gland was correct in 100%. In multiple-gland disease (n = 23), involvement of more than one gland was visualized in only 61% of the patients; however, in 91% of patients, at least one gland was localized. Surgical success-defined as postoperative normocalcemia-with this approach was 100%. All scans of normocalcemic control subjects were negative. Of 31 patients in whom a multinodular goiter coexisted, seven presented a significant radionuclide background at 120 minutes' scan. False-positive images were found together with those corresponding to the pathologic glands in only three cases.

CONCLUSIONS

99mTc-sestamibi is a highly reliable, sensitive, and specific technique for imaging of pathologic glands in hyperparathyroidism, especially in single-gland disease. It may be considered as a first line single-procedure when a preoperative topographic diagnosis is required.

Spectrum of alcohol-induced myocardial damage detected by indium-111-labeled monoclonal antimyosin antibodies

OBJECTIVES

We sought to determine the prevalence, intensity and evolving changes of myocardial damage detected by myocardial uptake of antimyosin antibodies in patients with alcohol-induced dilated cardiomyopathy, alcohol addicts attending a detoxification unit and healthy subjects with short-term alcohol consumption.

BACKGROUND

Evidence of alcohol-induced myocardial damage may be provided by myocardial uptake of indium-111-labeled monoclonal antimyosin antibodies. The spectrum of such damage in patients who are heavy drinkers (> 100 g for > 10 years), with or without cardiomyopathy, and the impact of short-term alcohol ingestion on antimyosin antibody uptake have not been adequately explored.

METHODS

One hundred twenty antimyosin studies were performed in 56 patients with dilated cardiomyopathy (group I), 15 alcohol addicts attending a detoxification unit (group II) and 6 volunteers for short-term alcohol ingestion (group III). Estimation of antibody uptake was calculated through a heart/lung ratio (HLR) (normal < 1.55).

RESULTS

The 56 patients in group I (54 men, 2 women; mean [+/-SD] age 46 +/- 11 years) had consumed 123 +/- 60 g/day of alcohol for 21 +/- 9 years, for a cumulative intake of 914 +/- 478 kg. Mean duration of symptoms was 46 +/- 49 months. Mean left ventricular end-diastolic diameter was 71 +/- 10 mm, and mean ejection fraction was 28 +/- 12%. No differences in New York Heart Association functional class, ventricular size or ejection fraction were noted between 28 active and 28 past consumers, except for the prevalence and intensity of antibody uptake (75% vs. 32%, p < 0.001) and HLR (1.75 +/- 0.26 vs. 1.49 +/- 0.17, p = 0.0001). In 19 patients in the active group restudied after alcohol withdrawal, antibody uptake decreased (from 1.76 +/- 0.17 to 1.55 +/- 0.19, p < 0.001), and ejection fraction improved (from 30 +/- 12% to 43 +/- 16%, (p < 0.001). No changes occurred in the 15 past consumers restudied. The 15 male patients in group II (mean age 36 +/- 4 years) had consumed 156 +/- 59 g/day for 17 +/- 5 years, for a cumulative alcohol intake of 978 +/- 537 kg, an amount similar to that in patients in group I, but antimyosin antibody uptake was detected in only 3 (20%) of 15 patients. None of six group III subjects developed antibody uptake after short-term ethanol ingestion. Despite the small sample size, the power to detect clinically relevant differences in most variables that did not reach statistical significance was amply sufficient.

CONCLUSIONS

In alcohol-induced dilated cardiomyopathy, alcohol withdrawal is associated with the reduction or disappearance of myocardial damage and improvement of function. The difference in prevalence of antimyosin antibody uptake in patients with and without cardiac disease who consume similar amounts of alcohol suggests the presence of those with different myocardial susceptibilities to alcohol. Short-term ethanol ingestion in healthy subjects does not induce detectable uptake of antimyosin antibodies.

Technetium-99m-methoxyisobutylisonitrile in localization of ectopic parathyroid adenoma

Preoperative localization of ectopic parathyroid lesions is crucial for the correct treatment of patients with primary hyperparathyroidism. Invasive and noninvasive procedures, including selective venography, ultrasound, CT and MRI provide limited sensitivity in the detection of ectopic lesions. We report three patients in whom 99mTc-MIBI scintigraphy accurately detected ectopic parathyroid adenomas and was instrumental in the cure for these patients. Technetium-99m-MIBI scintigraphy provides a simple and accurate noninvasive test for the detection of ectopic parathyroid adenomas.

Utility of 99mTc-sestamibi scintigraphy as a first-line imaging procedure in the preoperative evaluation of hyperparathyroidism

OBJECTIVE

The use of preoperative imaging in patients with hyperparathyroidism remains controversial. Many of the available techniques are insufficiently sensitive and specific to justify their routine use. We have evaluated the sensitivity and specificity of 99mTc-sestamibi scintigraphy in the management of patients with different forms of hyperparathyroidism.

DESIGN

Preoperative imaging evaluation was carried out by scintigraphic detection of pathological parathyroid glands using 99mTc-sestamibi as a radiotracer; confirmation of scan findings was obtained surgically.

PATIENTS

A group of 25 patients with primary (n = 21) or secondary (n = 4) hyperparathyroidism were studied. All were considered for surgical treatment.

MEASUREMENTS

In all cases parathyroid imaging was carried out by 99mTc-sestamibi scintigraphy together with at least one other imaging technique which included CT-scan, ultrasonography, MRI or 201TI/99mTc subtraction scintigraphy. Blood tests included measurements of total calcium and PTH.

RESULTS

99mTc-sestamibi scintigraphy correctly localized 20 out of 21 adenomas, giving a sensitivity of 95.2%, markedly higher than that obtained with the other imaging techniques (ultrasonography 75%, 201TI/99mTc subtraction scintigraphy 57.1%, CT-scan 41.7% and MRI 33%). Of a total of 17 glands identified surgically as hyperplastic and confirmed by pathological examination, 99mTc-sestamibi scintigraphy showed a positive image in 10, corresponding always to the larger abnormal glands (sensitivity 58.8%, higher than that observed with the other techniques). No false positive images were obtained with 99mTc-sestamibi. All the ectopic adenomas (n = 3) were identified preoperatively, which contributed significantly to the surgical approach.

CONCLUSION

In patients with hyperparathyroidism, 99mTc-sestamibi scintigraphy may be used as the single imaging technique as it shows a very high sensitivity and specificity in the preoperative localization of pathological parathyroid glands; the benefit of localizing parathyroid tissue prior to surgery in cases of ectopic adenomas clearly indicates that when an imaging procedure is required, this technique may be of great help in the management of hyperparathyroidism.

Presence, evolving changes, and prognostic implications of myocardial damage detected in idiopathic and alcoholic dilated cardiomyopathy by 111In monoclonal antimyosin antibodies

BACKGROUND

The clinical relevance of myocardial cell damage in dilated cardiomyopathy is uncertain. Myocardial uptake of 111In monoclonal antimyosin antibodies (MAA) was used to study myocardial damage in patients with idiopathic (IDC) and alcoholic (ADC) dilated cardiomyopathy and to assess its prognostic implications.

METHODS AND RESULTS

MAA and echocardiographic studies were performed in 117 patients. Intensity of antibody uptake was measured by heart-to-lung ratio (HLR) (normal < 1.55). Studies were repeated in survivors and patients who did not receive a cardiac transplant. Follow-up extended up to 62 months (mean, 23 +/- 16 months). Eighty-eight patients with IDC showed a 77% prevalence of abnormal MAA. After acute-onset IDC, reduction of HLR (1.81 +/- 0.2 to 1.56 +/- 0.1) (P = .007) with improvement in ejection fraction (EF) (35 +/- 10% to 46 +/- 14%) (P = .018) was observed. No changes in HLR or EF were detected in patients with chronic stable IDC. Twenty-nine patients with ADC showed a lower prevalence (48%) of abnormal MAA studies than those with IDC (P = .003). HLR was higher in 13 active (1.78 +/- 0.3) than in 16 past consumers (1.49 +/- 0.2) (P = .019); in the former, HLR decreased to 1.44 +/- 0.2 (P = .012), and EF improved (35 +/- 14% to 53 +/- 18%) (P = .05) after abstention. Intensities of uptake HLR of > 1.87 were associated with increased risk of death or transplantation.

CONCLUSIONS

In patients with IDC, variations of MAA uptake are detected in patients who present acutely but not in those with chronic stable disease. In patients with ADC, MAA uptake mainly depends on alcohol consumption. In both situations, reduction of uptake correlates with improvement of ventricular function. Higher intensities of MAA uptake are associated with a worse outcome. The intensity of antibody uptake, along with other clinical and functional variables, may be helpful in risk stratification of patients with dilated cardiomyopathy.

Evaluation of Indium-111 Antifibrin Monoclonal Antibody Imaging in Deep Venous Thrombosis Diagnosis

Objective:

To evaluate Indium-111 antifibrin monoclonal antibody in the diagnosis of deep vein thrombosis.

Design:

Prospective study in twelve patients undergoing major surgical treatment, including hip surgery, who would be considered at high risk of developing subsequent deep vein thrombosis.

Setting:

Departments of Angiology and Vascular Surgery, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.

Patients:

Twelve patients receiving surgical treatment.

Interventions:

Bilateral contrast phlebography was performed in all patients, combined with an ***immunoscintigraphic test of an Indium-111 labelled monoclonal ***antibody to fibrin. Patients with deep vein thrombosis were treated with full anticoagulation using heparin.

Main outcome measures:

The presence of thrombosis on phlebography and the presence of isotopic labelling of suspected deep vein thrombosis on immunoscintigraphic scanning.

Results:

Phlebography demonstrated venous thrombosis at 23 sites in veins, of which 22 were also detected by immunoscintigraphic scanning.

Conclusions:

Indium-111 labelled monoclonal antibodies to fibrin may provide an alternative method of investigation for suspected deep vein thrombosis as an alternative to other non-invasive diagnosis methodologies.

[Clinical application of radioimmunolocalization in colorectal cancer]

We present preliminary results of radioimmunolocalization (RIL) of colorectal cancer with 131I labelled F(ab')2 fragments from monoclonal anti CEA and anti CA 19.9 antibodies in 22 patients with colorectal cancer and in one patient with metastases of unknown origin and high CEA value. Positive images were obtained in 7 of 11 primary tumors from 10 patients evaluated preoperatively; in 2 of 3 recurrences; in 9 of 12 metastatic localizations and in the unknown primary tumor localized, finally in the cecum. One local recurrence was not detected by any diagnostic methods, but RIL. There was not false-positive images. Therefore, RIL appears as a promising method for the diagnosis and follow-up of colorectal cancer.

High prevalence of myocardial monoclonal antimyosin antibody uptake in patients with chronic idiopathic dilated cardiomyopathy

Monoclonal antimyosin antibody studies were undertaken to assess the presence of myocardial uptake in patients with chronic idiopathic dilated cardiomyopathy. Three groups were studied: 17 patients with chronic (greater than 12 months) idiopathic dilated cardiomyopathy, 12 patients with a large, poorly contracting left ventricle not due to dilated cardiomyopathy (control patients) and 8 normal individuals. The patients in the cardiomyopathy and control groups showed a similar degree of clinical and functional impairment. Imaging was undertaken 48 h after antimyosin injection. The heart/lung ratio of antimyosin uptake was used to assess the results. The mean ratio in the cardiomyopathy group was 1.83 +/- 0.36 (range 1.40 to 2.80), a value significantly higher than that obtained in the control patients without cardiomyopathy (mean 1.46 +/- 0.04, range 1.38 to 1.50) or normal subjects (mean 1.46 +/- 0.13, range 1.31 to 1.6) (p less than 0.01). No difference in the ratio was noted between the normal subjects and control patients. Abnormal antimyosin uptake was seen in 12 (70%) of the 17 patients with cardiomyopathy and in only 1 (8%) of the 12 control patients. Positive monoclonal antimyosin antibody studies are highly prevalent in chronic idiopathic dilated cardiomyopathy.